Association between VDR Gene Polymorphisms and Melanoma Susceptibility in a Colombian Population.

BACKGROUND: The vitamin D receptor (VDR) is responsible for mediating the effects of vitamin D through regulation of other gene transcriptions. There are several polymorphisms that alter the gene expression or the function of this protein. We aimed to analyze the association between two SNPs  of VDR gene and melanoma cancer in Colombian patients. METHODS: We included 120 healthy individual as controls and 120 melanoma cancer patients as cases . Patients in both groups were matched in terms of gender and age. The genotyping of rs731236 and rs2228570 polymorphisms was performed using PCR-RFLP. The SNPStats program was used to carry out the statistical analysis through a logistic regression model. RESULTS: Under dominant model, we found that rs2228570 polymorphism was associated with melanoma cancer risk (C/C vs C/T-T/T, OR: 5.10, 95% CI: 2.85-9.14), whereas rs731236 polymorphism was associated with a protective effect against this cancer (T/T vs T/C, OR: 0.27, 95% CI: 0.14-0.53). CONCLUSION: Our results suggested that both polymorphisms were involved in the development of melanoma cancer, increasing or decreasing this risk.

Association of toll-like receptors 2 and 6 polymorphism with clinical mastitis and production traits in Holstein cattle.

Mastitis is a costly disease of dairy cattle as it causes a loss in milk yield and milk quality in affected cows. Toll-like receptor (TLR) genes play a role in the host response to a variety of organisms including those inducing mastitis. In the present study, we investigated the polymorphism of TLR2, 4, 6 and 9 genes in Holstein cattle and their possible association with clinical mastitis (CM), milk somatic cell scores (SCS) and milk production traits. From a large commercial Holstein herd, thirty-eight blood samples were collected; 19 from cows without a previous lifetime history of mastitis (non-susceptible), and 19 from Holstein cows with at least three previous episodes of mastitis (susceptible). Genotyping of the four TLRs was done using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLPs) with Rsa1, MSP1, Hha1, HaeIII, and Taq1 enzymes guided with DNA sequencing. Seven novel non-synonymous single-nucleotide polymorphisms (SNPs) were identified among TLR2, 4, and 6 in susceptible animals. Association was found in Taq1-TLR2 gene polymorphism with CM, fat percentage and peak yield (PY). The association of Taq1-TLR6 and PY and lactation persistency was also shown. Mutations in TLRs that were repeatedly reported in susceptible cows provide potential genetic marker assisted selection (MAS) for mastitis resistance in dairy cattle.

Frequency of canine degenerative myelopathy SOD1:c.118G>A mutation in 22 dog breeds in Guadalajara, Mexico / Frecuencia de la mutación SOD1:c.118G>A de mielopatía degenerativa canina en 22 razas de perros en Guadalajara, México / Frequência da mutação SOD1: c.118G>A de mielopatía degenerativa canina em 22 raças de cães no Guadalajara, México

Abstract Background: Canine degenerative myelopathy (DM) is a late-onset disease that primarily affects large-breed dogs. The disease involves the spinal cord and produces progressive paresia and, eventually, complete loss of mobility. DM has been related to missense mutation c.118G>A in the SOD1 gene. Objective: To determine the genotypic and genic frequencies of DM in Mexico. Methods: In total, 330 samples from 22 different dog breeds were genotyped using the polymerase chain reaction and restriction fragment length polymorphisms (PCR-RFLP) technique. Results: The mutation was identified in 71 animals from 11 different breeds. Observed genic frequencies were 0.78 for the G allele and 0.14 for the A allele. Genotypic frequencies were 0.79 for the G/G wild-type, 0.14 for the G/A heterozygote, and 0.7 for the A/A homozygote. Conclusion: The genic frequency of this allele is high among the studied populations. A molecular marker program that identifies the DM mutation in breeding dogs should be implemented in order to reduce this frequency.

Resumen Antecedentes: La mielopatía degenerativa canina (MD) es una enfermedad progresiva de presentación tardía que afecta a la médula espinal, generalmente en caninos de razas grandes, y que produce paresis progresiva y eventual pérdida completa de la movilidad. Se ha relacionado con una mutación puntual por sustitución de bases en el gen SOD1 recientemente identificado como c.118G>A. Objetivo: Determinar las frecuencias genotípicas y génicas para la presentación de DM en México. Métodos: Se genotipificaron 330 muestras de perros de 22 razas mediante la técnica de reacción en cadena de la polimerasa y polimorfismos de longitud de fragmentos de restricción (PCR- RFLPs). Resultados: Se identificó la mutación en 71 animales de 11 razas diferentes. Las frecuencias génicas encontradas fueron de 0,78 para el alelo G y de 0,14 para el alelo A. Las frecuencias genotípicas fueron de 0,79 para el tipo silvestre G/G, 0,14 para el heterocigoto G/A y 0,7 para el homocigoto A/A. Conclusión: La frecuencia encontrada para la mutación es alta en las poblaciones estudiadas. La aplicación de un programa de selección asistida por marcadores moleculares contra la mutación causante de MDC en perros reproductores resultaría útil para reducir su frecuencia.

Resumo Antecedentes: A mielopatía degenerativa canina (MD) é uma doença progressiva de apresentação tardia que afeta a medula espinal geralmente de caninos de raças grandes e que produz paresia progressiva e eventualmente a perda completa da mobilidade. Tem sido relacionada com uma mutação pontual por substituição de bases no gen SOD1, recentemente identificado como c.118G>A. Objetivo: Determinar as frequências genotípicas e genéticas para a apresentação de DM no México. Métodos: Genotipagem de 330 amostras de cães de 22 raças por meio da técnica de reação em cadeia da polimerase e polimorfismos no comprimento de fragmentos de restrição (PCR- RFLPs). Resultados: A mutação foi identificada em 71 animais de 11 raças diferentes. As frequências gênicas encontradas foram de 0,78 para o alelo G e de 0,14 para o alelo A. As frequências genotípicas foram de 0,79 para o tipo silvestre G/G, 0,14 para o heterozigoto G/A e 0,7 para o homozigoto A/A. Conclusão: A frequência encontrada para a mutação é alta nas populações estudadas. A implementação de um programa de seleção assistida por marcadores moleculares contra a mutação que causa MDC seria útil para reduzir a sua frequência.

Identification of aphid (Hemiptera: Aphididae) species of economic importance in Kenya using DNA barcodes and PCR-RFLP-based approach.

Aphids are among pests of economic importance throughout the world. Together with transmitting plant viruses, aphids are capable of inflicting severe crop production losses. They also excrete honeydew that favours the growth of sooty mold which reduces the quality of vegetables and fruits and hence their market values. Rapid and accurate identification of aphids to the species level is a critical component in effective pest management and plant quarantine systems. Even though morphological taxonomy has made a tremendous impact on species-level identifications, polymorphism, morphological plasticity and immature stages are among the many challenges to accurate identification. In addition, their small size, presence of cryptic species and damaged specimens dictate the need for a strategy that will ensure timely and accurate identification. In this study, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)-based on mitochondrial cytochrome c oxidase subunit I gene and DNA barcoding were applied to identify different aphid species collected from different agro-ecological zones of Kenya. Three restriction enzymes RsaI, AluI and Hinf1 produced patterns that allowed unambiguous identification of the species except Aphis craccivora and Aphis fabae. Analyses of the barcode region indicated intraspecific and interspecific sequence divergences of 0.08 and 6.63%, respectively. DNA barcoding identified all species, including the morphologically indistinguishable A. craccivora and A. fabae and separated two subspecies of A. fabae. Based on these results, both PCR-RFLPs and DNA barcoding could provide quick and accurate tools for identification of aphid species within Aphididae subsequently aiding in effective pest management programmes and enhance plant quarantine systems.